In order to satisfy increasing demands of radio data traffic after the commercialization of a 4G communication system, efforts at developing an advanced 5G communication system or a pre-5G communication system have been made. For this reason, the 5G communication system or the pre-5G communication system is also referred to as a beyond-4G network communication system or a post-LTE system.
In order to accomplish a higher data transfer rate, the 5G communication system considers implementation at a super-high frequency (mmWave) band (e.g., such as a 60 GHz band). In order to obviate a path loss of a radio wave and increase a delivery distance of a radio wave at the super-high frequency band, various techniques such as a beamforming, a massive MIMO, a full dimensional MIMO (FD-MIMO), an array antenna, an analog beam-forming, and a large scale antenna are discussed in the 5G communication system.
Additionally, for an improvement in network of the 5G communication system, technical developments are made in an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, a device to device (D2D) communication, a wireless backhaul, a moving network, a cooperative communication, coordinated multi-points (CoMP), a reception interference cancellation, and the like.
Besides, in the 5G communication system, a hybrid FSK and QAM modulation (FQAM) and a sliding window superposition coding (SWSC) are developed as advanced coding modulation (ACM) schemes, and a filter bank multi carrier (FBMC), a non orthogonal multiple access (NOMA), and a sparse code multiple access (SCMA) are also developed as advanced access techniques.
There is a growing demand for various communication services such as internet of things (IoT) in addition to the existing communication services. To meet such a demand, a scenario of providing several communication services by using frequency/space resources divided from the existing frequency/space resources is being considered. For an efficient use of limited frequency/space resources, different communication services should coexist on adjacent frequency resources. However, in this case, problems such as mutual interference and hardware issue of an analog-digital converter (ADC) or a digital-analog converter (DAC) may be caused. If a solution of such problems is not provided, the system performance of each service will be greatly degraded. In particular, when the coverage provided by the system is different, or when base stations of each system are in different locations, the above problems may become more serious.
In order to solve these problems, an open loop transmission which does not require channel state information is advantageous in comparison with a closed loop transmission. Because feedback overhead is reduced, there is an advantage that a related circuit is not used, power consumption and complexity are reduced, and signaling overhead is reduced.
Also, in case of a terminal, it is advantageous to have one radio frequency (RF) chain. A current LTE terminal has two or more reception RF chains, but having only one RF chain is advantageous in that cost can be reduced by 30%, power consumption is reduced, and baseband-related complexity is reduced.
Further, in multi-user multi-input multi-output (MU-MIMO), a transmission rate is improved and the number of users capable of simultaneous access is increased.